Currently, liquid crystal displays are widely used to personal computers, portable electronics and the like.
This liquid crystal display, as shown in FIG. 1, is generally constituted by forming transparent electrodes 3, alignment layers 9, color filters 4 and black matrixes 5 between two transparent substrates 1, locating polarizers 2 outside two transparent substrates 1, installing a sealing material 10 at the periphery of two transparent substrates 1, and encapsulating liquid crystal 7 in a gap between two transparent substrates 1 located on opposite sides of the sealing material 10 interposed. In this liquid crystal display, spacers 8 are used for the purpose of regulating the distance of two transparent substrates 1 and retaining a proper thickness (cell gap) of a liquid crystal layer.
Conventional liquid crystal displays have been fabricated by the following step.
1) A color filter substrate, in which a black matrix, a color filter, a transparent electrode, an alignment layer and the like are formed on a transparent substrate such as glass, and an electrode substrate, in which a pixel electrode such as a transistor, a diode device is formed on a transparent substrate, are previously fabricated. And, a driving circuit to drive the electrode is formed outside a portion corresponding to the color filter.
2) After the spacers are sprayed on the color filter substrate with a wet type or dry type sprayer, the color filter substrate on which the spacers are sprayed and the electrode substrate are bonded to each other while the electrode is carefully aligned with the color filter, using the sealing material. In addition, when applying the sealing material, a portion to be a filling port of liquid crystal is opened.
3) The sealing material is heated to be cured while applying an appropriate pressure to the bonded two substrates in such a way that the gap between the substrates becomes proper through the spacers.
4) In vacuum, the liquid crystal is filled by capillarity and then excessively filled liquid crystal is purged by the application of pressure and the filling port is sealed with an end-sealing material.
5) Spacers adhered to a portion corresponding to a driving circuit outside the sealing material and liquid crystal overflowing by the application of pressure are cleaned.
On the other hand, though in recent years, upsizing of a substrate is required, a conventional method, namely liquid crystal filling by capillarity, took too much time. And so, in order to resolve such a problem, there is proposed a method of producing by a drop method of liquid crystal, in which a sealing material is applied in advance and a precise amount of liquid crystal is dropped in a section divided with the sealing material and then substrates are bonded.
However, when the drop method of liquid crystal is employed, a problem that spacers sprayed even to the area outside the sealing material in the conventional spraying method cannot be removed has arises since there is not a cleaning step corresponding to the paragraph 5) of the conventional method of fabricating.
And, in recent years, there is fabricated a reflective and semi-transparent liquid crystal display, in which a part of the surfaces of pixels formed on either one of the substrates is provided with reflection layers having fine concavities and convexities.
But, in such a liquid crystal display, since there is produced a difference in height between two areas provided with a reflection layer and not provided with a reflection layer, particles sprayed at lower area by a conventional spraying method cannot contribute to retain a cell gap and a problem that the number of spacers to be sprayed must be increased in order to retain the cell gap has arisen.
In order to resolve such problems, methods of dispersing spacers, in which spacer dispersion liquid obtainable by dispersing spacers in a medium based on water is ejected on a substrate with an ink-jet system, are disclosed in Japanese Kokai Publication Hei-11-24083, Japanese Kokai Publication Hei-11-281935 and Japanese Kokai Publication 2001-188235. When a dispersing method using an ink-jet system is employed, since it is possible to disperse spacers in arbitrary region, it can be said that it is effective for resolving the problem.
However, in Japanese Kokai Publication 2001-188235, there is not described in detail a method of selecting a medium which can be used, and when a dispersion medium, which is based on water and has high surface tension, is used like Japanese Kokai Publication Hei-11-24083 and Japanese Kokai Publication Hei-11-281935, a problem that particles cohere arises. And, if the cohesion of particles occurs in a shading section (a non-display section), there is not a problem, but since the width of the shading section such as a black matrix has become narrow in recent years, it has become considerably difficult to constrain the cohesion of particles in a prescribed section even when alignment was carried out. In addition, when the cohesion of particles occurred not in a non-display section but in a display section, since transmittance was reduced, there was the case where display performance of a liquid crystal display such as contrast was degraded.
Further, in Japanese Kokai Publication Hei-11-24083, there was a description that when a medium having a low boiling point and low surface tension was used, spacers were resistant to cohesion, but when a large amount of spacer dispersion liquid was ejected in a certain area for the purpose of increasing the number of spacers to be sprayed, there was yet a problem of the occurrence of cohesion.